<div dir="ltr"><div><div><div>See below:</div><div><br><div class="gmail_quote">On Thu, Aug 21, 2008 at 2:03 PM, Francois Tallet (ftallet) <span dir="ltr"><<a href="mailto:ftallet@cisco.com">ftallet@cisco.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div>
<div dir="ltr" align="left"><span><font face="Arial" size="2">Just a comment on section 3.3's summary:</font></span></div>
<div><div class="Ih2E3d">
<p style="margin:0px;font:13px Arial"><em><strong>Section
3.3:</strong></em></p>
<p style="margin:0px;font:13px Arial"><em><strong>There was one comment that
there are no transient loops in Spanning Tree. This is incorrect. Transient
loops, however unlikely, are possible with Spanning Tree.</strong></em></p>
</div><p style="min-height:15px;margin:0px;font:13px Arial"><br><span><font size="2">You actually made the comment that some
people were claiming there could not ever be a loop with STP (I will never make
that claim as I would have a hard time justifying what I'd been working on for
10 years;-)</font></span></p></div></div></blockquote><div><br></div><div>[dee3] Of course I can't actually tell what is in some else's mind or what their motivations are but I've heard many statement that would give many people the false impression that there can never be temporary loops with any version of spanning tree. I've seem presentations comparing spanning tree with "routing" that give the false impressions that no version of spanning tree can ever have a transient loop but that "routing protocols" routinely have persistent loops.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div><p style="min-height:15px;margin:0px;font:13px Arial"><span><font size="2"></font></span></p>
<p style="min-height:15px;margin:0px;font:13px Arial"><span><font size="2">The real comment is that the draft is
using what can be considered <strong>exceptional </strong>STP failure scenarios
to justify TRILL's <strong>normal</strong> way of operation.</font></span></p></div></div></blockquote><div><br></div><div>[dee3] This document is not the protocol specification. It is the problem statement and applicability document. It sets only very broad bounds on how whatever TRILL protocol is adopted would work. If you want to claim that it would <span class="Apple-style-span" style="font-weight: bold; ">allow</span> such a "way of operation", fine. But I don't see it as specifying or justifying any particular "normal way of operation".<br>
</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div><p style="min-height:15px;margin:0px;font:13px Arial"><span><font size="2">I'll be happy
if your next draft simply acknowledges that TRILL does not attempt to prevent
temporary loops the way STP does.</font></span></p></div></div></blockquote><div><br></div><div>[dee3] It seems unlikely that the TRILL protocol will do much of anything the same way STP does and I think that is pretty clear from the document. As is always the case when you are requesting a change in a draft, it would be good to provide a specific wording change suggestion.</div>
<div> <span class="Apple-style-span" style="font-family: Arial; "> </span></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div>
<p style="min-height:15px;margin:0px;font:13px Arial"><span><font size="2">Regards,</font></span></p>
<p style="min-height:15px;margin:0px;font:13px Arial"><span><font size="2">Francois</font></span></p></div></div></blockquote><div><br></div><div>Donald</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><div><p style="min-height:15px;margin:0px;font:13px Arial"><span><font size="2"></font></span></p></div>
<blockquote dir="ltr" style="padding-left:5px;margin-left:5px;border-left:#000000 2px solid;margin-right:0px">
<div lang="en-us" dir="ltr" align="left">
<hr>
<font face="Tahoma" size="2"><b>From:</b> <a href="mailto:rbridge-bounces@postel.org" target="_blank">rbridge-bounces@postel.org</a>
[mailto:<a href="mailto:rbridge-bounces@postel.org" target="_blank">rbridge-bounces@postel.org</a>] <b>On Behalf Of </b>Donald
Eastlake<br><b>Sent:</b> Wednesday, August 20, 2008 8:43 PM<br><b>To:</b>
<a href="mailto:rbridge@postel.org" target="_blank">rbridge@postel.org</a><br><b>Subject:</b> [rbridge] WGLC comments on problem and
applicability statement<br></font><br></div><div><div></div><div class="Wj3C7c">
<div></div>
<div dir="ltr">
<div>
<p style="margin:0px;font:13px Arial">Hi,</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Below is my summary of the Working
Group Last Call comments on draft-ietf-trill-prob-04.txt.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">General:</p>
<p style="margin:0px;font:13px Arial">There appears to be a rough consensus
that the draft is excessively critical of spanning tree and this should be
corrected in several places.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Abstract:</p>
<p style="margin:0px;font:13px Arial">There were a number of complaints
about the abstract; however the abstract is reasonably consistent with the
body. Rather than considering such complaints twice, any problems with the
body should be fixed and then the abstract adjusted to be consistent with the
revised body.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Introduction:</p>
<p style="margin:0px;font:13px Arial">Comments in the draft concerning
spanning tree slow convergence need, at a minimum, to be qualified to indicate
they generally do not apply to RSTP.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Section 2:</p>
<p style="margin:0px;font:13px Arial">There were complaints when 802.1Q was
referenced, saying that previous amendment that were incorporated such as
802.1s should be referenced instead. And there were complaints when amendments
such as 802.1s were referenced in other parts of the document saying that they
no longer exist and no amendments that have been rolled into the 802.1Q base
document should be mentioned separately.</p></div>
<blockquote style="border-right:medium none;padding-right:0px;border-top:medium none;padding-left:0px;padding-bottom:0px;margin:0px 0px 0px 40px;border-left:medium none;padding-top:0px;border-bottom:medium none"><span style="font-family:Arial">In the normal case, when
not otherwise qualified, "802.1Q" should refer to the current IEEE 802.1Q
standard at the time this draft is published and as specified in the
References section; however, there is no particular harm in referring to
earlier amendments that have been rolled into 802.1Q as long as their status
is mentioned.</span><br></blockquote>
<div>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Section 2.1:</p>
<p style="margin:0px;font:13px Arial">There was one comment that thicknet,
thinnet, and hubs should not be mentioned because they no longer exist but the
reference to them is historical and there are still hubs, at least, in
use.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Section 2.2:</p>
<p style="margin:0px;font:13px Arial">There is a statement in the draft
intended to compare ECMP link-state with non-ECMP link state which may appear
to be a comparison between ECMP link-state with STP. This should be
clarified.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Section 2.3:</p>
<p style="margin:0px;font:13px Arial">The referenced paper (reference [5]
in the draft) contains serious errors and should probably not be referenced.
But, as Francois Tallet said, "RSTP can indeed suffer from the usual count to
infinity issue specific to distance vector protocols that can delay the
convergence by few seconds."</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Section 2.5:</p>
<p style="margin:0px;font:13px Arial">That there are actually 65 trees
available with MSTP and that each is used for forwarding a non-overlapping set
of VLANs should be clarified.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Section 3.3:</p>
<p style="margin:0px;font:13px Arial">There was one comment that there are
no transient loops in Spanning Tree. This is incorrect. Transient loops,
however unlikely, are possible with Spanning Tree.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Section 3.4:</p>
<p style="margin:0px;font:13px Arial">One missing reference.</p>
<p style="min-height:15px;margin:0px;font:13px Arial"><br></p>
<p style="margin:0px;font:13px Arial">Thanks,</p>
<p style="margin:0px;font:13px Arial">Donald (co-chair)</p>
<p style="margin:0px;font:13px Arial">=============================</p>
<p style="margin:0px;font:13px Arial">Donald E. Eastlake 3rd
+1-508-634-2066 (home)</p>
<p style="margin:0px;font:13px Arial">155 Beaver Street</p>
<p style="margin:0px;font:13px Arial">Milford, MA 01757 USA</p>
<p style="margin:0px;font:13px Arial;color:#0018ea"><span style="text-decoration:underline"><a href="mailto:d3e3e3@gmail.com" target="_blank">d3e3e3@gmail.com</a></span></p>
<p style="margin:0px;font:13px Arial;color:#0018ea"><br></p></div></div></div></div></blockquote></div></blockquote></div>=============================<br> Donald E. Eastlake 3rd +1-508-634-2066 (home)<br> 155 Beaver Street<br>
Milford, MA 01757 USA<br> <a href="mailto:d3e3e3@gmail.com">d3e3e3@gmail.com</a><br>
</div></div></div></div>